(Image courtesy of Purdue University/Kayla Wiles)
One possible complication of diabetes that can be particularly difficult to treat is a foot ulcer, or a sore that’s usually located on the bottom of the foot. According to the American Pediatric Medical Association, about 15 percent of people with diabetes will develop a foot ulcer at some point.
And according to the American College of Foot and Ankle Surgeons, almost 85 percent of toe, foot and leg amputations are the eventual result of foot wounds that don’t heal properly or that return after appearing to heal.
(Video courtesy of Purdue University)
So finding new ways to help foot ulcers heal may be an important step toward reducing amputations. As part of this effort, researchers at Purdue University have developed a novel solution — an insole that can deliver oxygen to ulcers in a targeted way.
These insoles are designed to be used in combination with other treatments, such as removing damaged tissue from the surface of the wound and wearing a cast to help protect and keep weight off the area.
The insoles are created by using lasers to shape silicone rubber and form reservoirs for oxygen in the area where a person’s ulcer is located.
”Laser machining helps us to … target just the wound site, which is hypoxic,” or low in oxygen, “rather than poison the rest of the foot with too much oxygen,” notes Hongjie Jiang, a postdoctoral researcher in electrical and computer engineering at Purdue who played a leading role in developing the insoles.
As designed, the insole should be able to deliver oxygen to a wound for at least 8 hours a day for a person weighing 117 to 179 pounds (53 to 81 kilograms), but it could be customized to fit someone of any weight.
The next step for the research team is to test the insole on actual patients with foot ulcers to assess how they affect the healing process, as well as look into ways to 3D-print the insoles rather than cut them using lasers.
Eventually, they envision a system in which a doctor prescribes the insoles and sends the manufacturer photos and other information to create a “wound profile,” after which the patient receives a package of customized, oxygen-filled insoles in the mail.